/MAT/LAW50 (VISC_HONEY)

Block Format Keyword This law describes a three dimension orthotropic nonlinear elasto-plastic material, usually used to model honeycomb or foam material.

Nonlinear elastoplastic behavior can be specified for each othrotropic direction and shear as function of strain or volumetric strain. All these degrees of freedom are fully uncoupled. The material is fully compressible. Tension and shear strain-based failure criteria can be specified. This honeycomb material is like material LAW28 except that LAW50 includes strain rate dependency.

Format

(1)	(3)	(5)
/MAT/LAW50/`mat_ID`/`unit_ID` or /MAT/VISC_HONEY/`mat_ID`/`unit_ID`
`mat_title`
$ρ_{i}$
`E`₁₁	`E`₂₂	`E`₃₃
`G`₁₂	`G`₂₃	`G`₃₁
`asrate`

Failure plastic strain and yield stress in normal direction 11, 22, 33

(1)	(2)	(3)	(4)	(5)	(6)	(7)	(9)
`Iflag`₁	$ε_{\max 11}$		$ε_{\max 22}$		$ε_{\max 33}$
`fctID`_11-1	`fctID`_11-2	`fctID`_11-3	`fctID`_11-4	`fctID`_11-5
`Fscale`_11-1		`Fscale`_11-2		`Fscale`_11-3		`Fscale`_11-4	`Fscale`_11-5
${\dot{ε}}_{11 - 1}$		${\dot{ε}}_{11 - 2}$		${\dot{ε}}_{11 - 3}$		${\dot{ε}}_{11 - 4}$	${\dot{ε}}_{11 - 5}$
`fctID`_22-1	`fctID`_22-2	`fctID`_22-3	`fctID`_22-4	`fctID`_22-5
`Fscale`_22-1		`Fscale`_22-2		`Fscale`_22-3		`Fscale`_22-4	`Fscale`_22-5
${\dot{ε}}_{22 - 1}$		${\dot{ε}}_{22 - 2}$		${\dot{ε}}_{22 - 3}$		${\dot{ε}}_{22 - 4}$	${\dot{ε}}_{22 - 5}$
`fctID`_33-1	`fctID`_33-2	`fctID`_33-3	`fctID`_33-4	`fctID`_33-5
Fscale_33-1		Fscale_33-2		Fscale_33-3		Fscale_33-4	Fscale_33-5
${\dot{ε}}_{33 - 1}$		${\dot{ε}}_{33 - 2}$		${\dot{ε}}_{33 - 3}$		${\dot{ε}}_{33 - 4}$	${\dot{ε}}_{33 - 5}$

Shear failure plastic strain and shear yield stress in direction 12, 23, 31

(1)	(2)	(3)	(4)	(5)	(6)	(7)	(9)
`Iflag`₂	$ε_{\max 12}$		$ε_{\max 23}$		$ε_{\max 31}$
`fctID`_12-1	`fctID`_12-2	`fctID`_12-3	`fctID`_12-4	`fctID`_12-5
`Fscale`_12-1		`Fscale`_12-2		`Fscale`_12-3		`Fscale`_12-4	`Fscale`_12-5
${\dot{ε}}_{12 - 1}$		${\dot{ε}}_{12 - 2}$		${\dot{ε}}_{12 - 3}$		${\dot{ε}}_{12 - 4}$	${\dot{ε}}_{12 - 5}$
`fctID`_23-1	`fctID`_23-2	`fctID`_23-3	`fctID`_23-4	`fctID`_23-5
`Fscale`_23-1		`Fscale`_23-2		`Fscale`_23-3		`Fscale`_23-4	`Fscale`_23-5
${\dot{ε}}_{23 - 1}$		${\dot{ε}}_{23 - 2}$		${\dot{ε}}_{23 - 3}$		${\dot{ε}}_{23 - 4}$	${\dot{ε}}_{23 - 5}$
`fctID`_31-1	`fctID`_31-2	`fctID`_31-3	`fctID`_31-4	`fctID`_31-5
`Fscale`_31-1		`Fscale`_31-2		`Fscale`_31-3		`Fscale`_31-4	`Fscale`_31-5
${\dot{ε}}_{31 - 1}$		${\dot{ε}}_{31 - 2}$		${\dot{ε}}_{31 - 3}$		${\dot{ε}}_{31 - 4}$	${\dot{ε}}_{31 - 5}$

Definitions

Field	Contents	SI Unit Example
`mat_ID`	Material identifier (Integer, maximum 10 digits)
`unit_ID`	Unit Identifier (Integer, maximum 10 digits)
`mat_title`	Material title (Character, maximum 100 characters)
$ρ_{i}$	Initial material density (Real)	$[\frac{kg}{m^{3}}]$
`E`₁₁	Young's modulus in orthotropic direction 1 (Real)	$[Pa]$
`E`₂₂	Young's modulus in orthotropic direction 2 (Real)	$[Pa]$
`E`₃₃	Young's modulus in orthotropic direction 3 (Real)	$[Pa]$
`G`₁₂	Shear modulus in direction 12 (Real)	$[Pa]$
`G`₂₃	Shear modulus in direction 23 (Real)	$[Pa]$
`G`₃₁	Shear modulus in direction 31 (Real)	$[Pa]$
`asrate`	Strain rate filtering cutoff frequency (Real)	$[Hz]$
`Iflag`₁	Strain formulation for yield functions 11, 22, and 33. 6 = 0 Yield stress is a function of $μ$ (volumetric strains) = 1 Yield stress is a function of $ε$ (strains) = -1 Yield stress is a function of $- ε$ (Integer)
$ε_{\max 11}$	Failure plastic strain in direction 11. (Real)
$ε_{\max 22}$	Failure plastic strain in direction 22. (Real)
$ε_{\max 33}$	Failure plastic strain in direction 33. (Real)
`fctID`_11-1	Identifier of yield stress function number 1 in direction 11. (Integer)
`fctID`_11-2	Identifier of yield stress function number 2 in direction 11. (Integer)
`fctID`_11-3	Identifier of yield stress function number 3 in direction 11. (Integer)
`fctID`_11-4	Identifier of yield stress function number 4 in direction 11. (Integer)
`fctID`_11-5	Identifier of yield stress function number 5 in direction 11. (Integer)
`Fscale`_11-1	Scale factor for yield stress function number 1 in direction 11, `fctID`_11-1. Default = 1.0 (Real)	$[Pa]$
`Fscale`_11-2	Scale factor for yield stress function number 2 in direction 11, `fctID`_11-2. Default = 1.0 (Real)	$[Pa]$
`Fscale`_11-3	Scale factor for yield stress function number 3 in direction 11, `fctID`_11-3. Default = 1.0 (Real)	$[Pa]$
`Fscale`_11-4	Scale factor for yield stress function number 4 in direction 11, `fctID`_11-4. Default = 1.0 (Real)	$[Pa]$
`Fscale`_11-5	Scale factor for yield stress function number 5 in direction 11, `fctID`_11-5. Default = 1.0 (Real)	$[Pa]$
${\dot{ε}}_{11 - 1}$	Strain rate for function number 1 in direction 11, `fctID`_11-1. (Real)	$[\frac{1}{s}]$
${\dot{ε}}_{11 - 2}$	Strain rate for function number 2 in direction 11, `fctID`_11-2. (Real)	$[\frac{1}{s}]$
${\dot{ε}}_{11 - 3}$	Strain rate for function number 3 in direction 11, `fctID`_11-3. (Real)	$[\frac{1}{s}]$
${\dot{ε}}_{11 - 4}$	Strain rate for function number 4 in direction 11, `fctID`_11-4. (Real)	$[\frac{1}{s}]$
${\dot{ε}}_{11 - 5}$	Strain rate for function number 5 in direction 11, `fctID`_11-5. (Real)	$[\frac{1}{s}]$
`fctID`_22-1	Identifier of yield stress function number 1 in direction 22. (Integer)
`fctID`_22-2	Identifier of yield stress function number 2 in direction 22. (Integer)
`fctID`_22-3	Identifier of yield stress function number 3 in direction 22. (Integer)
`fctID`_22-4	Identifier of yield stress function number 4 in direction 22. (Integer)
`fctID`_22-5	Identifier of yield stress function number 5 in direction 22. (Integer)
`Fscale`_22-1	Scale factor for yield stress function number 1 in direction 22, `fctID`_22-1. Default = 1.0 (Real)	$[Pa]$
`Fscale`_22-2	Scale factor for yield stress function number 2 in direction 22, `fctID`_22-2. Default = 1.0 (Real)	$[Pa]$
`Fscale`_22-3	Scale factor for yield stress function number 3 in direction 22, `fctID`_22-3. Default = 1.0 (Real)	$[Pa]$
`Fscale`_22-4	Scale factor for yield stress function number 4 in direction 22, `fctID`_22-4. Default = 1.0 (Real)	$[Pa]$
`Fscale`_22-5	Scale factor for yield stress function number 5 in direction 22, `fctID`_22-5. Default = 1.0 (Real)	$[Pa]$
${\dot{ε}}_{22 - 1}$	Strain rate for function number 1 in direction 22, `fctID`_22-1. (Real)	$[\frac{1}{s}]$
${\dot{ε}}_{22 - 2}$	Strain rate for function number 2 in direction 22, `fctID`_22-2. (Real)	$[\frac{1}{s}]$
${\dot{ε}}_{22 - 3}$	Strain rate for function number 3 in direction 22, `fctID`_22-3. (Real)	$[\frac{1}{s}]$
${\dot{ε}}_{22 - 4}$	Strain rate for function number 4 in direction 22, `fctID`_22-4. (Real)	$[\frac{1}{s}]$
${\dot{ε}}_{22 - 5}$	Strain rate for function number 5 in direction 22, `fctID`_22-5. (Real)	$[\frac{1}{s}]$
`fctID`_33-1	Identifier of yield stress function number 1 in direction 33. (Integer)
`fctID`_33-2	Identifier of yield stress function number 2 in direction 33. (Integer)
`fctID`_33-3	Identifier of yield stress function number 3 in direction 33. (Integer)
`fctID`_33-4	Identifier of yield stress function number 4 in direction 33. (Integer)
`fctID`_33-5	Identifier of yield stress function number 5 in direction 33. (Integer)
`Fscale`_33-1	Scale factor for yield stress function number 1 in direction 33, `fctID`_33-1. Default = 1.0 (Real)	$[Pa]$
`Fscale`_33-2	Scale factor for yield stress function number 2 in direction 33, `fctID`_33-2. Default = 1.0 (Real)	$[Pa]$
`Fscale`_33-3	Scale factor for yield stress function number 3 in direction 33, `fctID`_33-3 Default = 1.0 (Real)	$[Pa]$
`Fscale`_33-4	Scale factor for yield stress function number 4 in direction 33, `fctID`_33-4 Default = 1.0 (Real)	$[Pa]$
`Fscale`_33-5	Scale factor for yield stress function number 5 in direction 33, `fctID`_33-5 Default = 1.0 (Real)	$[Pa]$
${\dot{ε}}_{33 - 1}$	Strain rate for function number 1 in direction 33, `fctID`_33-1 (Real)	$[\frac{1}{s}]$
${\dot{ε}}_{33 - 2}$	Strain rate for function number 2 in direction 33, `fctID`_33-2 (Real)	$[\frac{1}{s}]$
${\dot{ε}}_{33 - 3}$	Strain rate for function number 3 in direction 33, `fctID`_33-3 (Real)	$[\frac{1}{s}]$
${\dot{ε}}_{33 - 4}$	Strain rate for function number 4 in direction 33, `fctID`_33-4 (Real)	$[\frac{1}{s}]$
${\dot{ε}}_{33 - 5}$	Strain rate for function number 5 in direction 33, `fctID`_33-5 (Real)	$[\frac{1}{s}]$
`Iflag`₂	Strain formulation for shear yield functions 12, 23, and 31. 6 = 0 Yield stress is a function of $μ$ (volumetric strains) = 1 Yield stress is a function of $ε$ (strains) = -1 Yield stress is a function of $- ε$ (Integer)
$ε_{\max 12}$	Shear failure plastic strain in direction 12 (Real)
$ε_{\max 23}$	Shear failure plastic strain in direction 23 (Real)
$ε_{\max 31}$	Shear failure plastic strain in direction 31 (Real)
`fctID`_12-1	Identifier of shear yield stress function number 1 in direction 12 (Integer)
`fctID`_12-2	Identifier of shear yield stress function number 2 in direction 12 (Integer)
`fctID`_12-3	Identifier of shear yield stress function number 3 in direction 12 (Integer)
`fctID`_12-4	Identifier of shear yield stress function number 4 in direction 12 (Integer)
`fctID`_12-5	Identifier of shear yield stress function number 5 in direction 12 (Integer)
`Fscale`_12-1	Scale factor for shear yield stress function number 1 in direction 12, `fctID`_12-1 Default = 1.0 (Real)	$[Pa]$
`Fscale`_12-2	Scale factor for shear yield stress function number 2 in direction 12, `fctID`_12-2 Default = 1.0 (Real)	$[Pa]$
`Fscale`_12-3	Scale factor for shear yield stress function number 3 in direction 12, `fctID`_12-3 Default = 1.0 (Real)	$[Pa]$
`Fscale`_12-4	Scale factor for shear yield stress function number 4 in direction 12, `fctID`_12-4 Default = 1.0 (Real)	$[Pa]$
`Fscale`_12-5	Scale factor for shear yield stress function number 5 in direction 12, `fctID`_12-5 Default = 1.0 (Real)	$[Pa]$
${\dot{ε}}_{12 - 1}$	Strain rate for function number 1 in direction 12, `fctID`_12-1 (Real)	$[\frac{1}{s}]$
${\dot{ε}}_{12 - 2}$	Strain rate for function number 2 in direction 12, `fctID`_12-2 (Real)	$[\frac{1}{s}]$
${\dot{ε}}_{12 - 3}$	Strain rate for function number 3 in direction 12, `fctID`_12-3 (Real)	$[\frac{1}{s}]$
${\dot{ε}}_{12 - 4}$	Strain rate for function number 4 in direction 12, `fctID`_12-4 (Real)	$[\frac{1}{s}]$
${\dot{ε}}_{12 - 5}$	Strain rate for function number 5 in direction 12, `fctID`_12-5 (Real)	$[\frac{1}{s}]$
`fctID`_23-1	Identifier of shear yield stress function number 1 in direction 23 (Integer)
`fctID`_23-2	Identifier of shear yield stress function number 2 in direction 23 (Integer)
`fctID`_23-3	Identifier of shear yield stress function number 3 in direction 23 (Integer)
`fctID`_23-4	Identifier of shear yield stress function number 4 in direction 23 (Integer)
`fctID`_23-5	Identifier of shear yield stress function number 5 in direction 23 (Integer)
`Fscale`_23-1	Scale factor for shear yield stress function number 1 in direction 23, `fctID`_23-1 Default = 1.0 (Real)	$[Pa]$
`Fscale`_23-2	Scale factor for shear yield stress function number 2 in direction 23, `fctID`_23-2 Default = 1.0 (Real)	$[Pa]$
`Fscale`_23-3	Scale factor for shear yield stress function number 3 in direction 23, `fctID`_23-3 Default = 1.0 (Real)	$[Pa]$
`Fscale`_23-4	Scale factor for shear yield stress function number 4 in direction 23, `fctID`_23-4 Default = 1.0 (Real)	$[Pa]$
`Fscale`_23-5	Scale factor for shear yield stress function number 5 in direction 23, `fctID`_23-5 Default = 1.0 (Real)	$[Pa]$
${\dot{ε}}_{23 - 1}$	Strain rate for function number 1 in direction 23, `fctID`_23-1 (Real)	$[\frac{1}{s}]$
${\dot{ε}}_{23 - 2}$	Strain rate for function number 2 in direction 23, `fctID`_23-2 (Real)	$[\frac{1}{s}]$
${\dot{ε}}_{23 - 3}$	Strain rate for function number 3 in direction 23, `fctID`_23-3 (Real)	$[\frac{1}{s}]$
${\dot{ε}}_{23 - 4}$	Strain rate for function number 4 in direction 23, `fctID`_23-4 (Real)	$[\frac{1}{s}]$
${\dot{ε}}_{23 - 5}$	Strain rate for function number 5 in direction 23, `fctID`_23-5 (Real)	$[\frac{1}{s}]$
`fctID`_31-1	Identifier of shear yield stress function number 1 in direction 31 (Integer)
`fctID`_31-2	Identifier of shear yield stress function number 2 in direction 31 (Integer)
`fctID`_31-3	Identifier of shear yield stress function number 3 in direction 31 (Integer)
`fctID`_31-4	Identifier of shear yield stress function number 4 in direction 31 (Integer)
`fctID`_31-5	Identifier of shear yield stress function number 5 in direction 31 (Integer)
`Fscale`_31-1	Scale factor for shear yield stress function number 1 in direction 31, `fctID`_31-1 Default = 1.0 (Real)	$[Pa]$
`Fscale`_31-2	Scale factor for shear yield stress function number 2 in direction 31, `fctID`_31-2 Default = 1.0 (Real)	$[Pa]$
`Fscale`_31-3	Scale factor for shear yield stress function number 3 in direction 31, `fctID`_31-3 Default = 1.0 (Real)	$[Pa]$
`Fscale`_31-4	Scale factor for shear yield stress function number 4 in direction 31, `fctID`_31-4 Default = 1.0 (Real)	$[Pa]$
`Fscale`_31-5	Scale factor for shear yield stress function number 5 in direction 31, `fctID`_31-5 Default = 1.0 (Real)	$[Pa]$
${\dot{ε}}_{31 - 1}$	Strain rate for function number 1 in direction 31, `fctID`_31-1 (Real)	$[\frac{1}{s}]$
${\dot{ε}}_{31 - 2}$	Strain rate for function number 2 in direction 31, `fctID`_31-2 (Real)	$[\frac{1}{s}]$
${\dot{ε}}_{31 - 3}$	Strain rate for function number 3 in direction 31, `fctID`_31-3 (Real)	$[\frac{1}{s}]$
${\dot{ε}}_{31 - 4}$	Strain rate for function number 4 in direction 31, `fctID`_31-4 (Real)	$[\frac{1}{s}]$
${\dot{ε}}_{31 - 5}$	Strain rate for function number 5 in direction 31, `fctID`_31-5 (Real)	$[\frac{1}{s}]$

Example (Honeycomb)


#RADIOSS STARTER
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/UNIT/1
unit for mat
                 kg                  mm                  ms
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
#-  2. MATERIALS:
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/MAT/LAW50/1/1
Honeycomb material
#              RHO_I
             2.87E-8
#                E11                 E22                 E33
               .1655              .01655              .01655
#                G12                 G23                 G31
               .1103              .00552               .1103
#             asrate
                   0
#   Iflag1           Eps_max11           Eps_max22           Eps_max33
        -1                  .1                  .2                  .2
#fctID11-1 fctID11-2 fctID11-3 fctID11-4 fctID11-5
         2        12        13        13         0
#        Fscale_11-1         Fscale_11-2         Fscale_11-3         Fscale_11-4         Fscale_11-5
                   0                   0                   0                   0                   0
#      Eps_rate_11-1       Eps_rate_11-2       Eps_rate_11-3       Eps_rate_11-4       Eps_rate_11-5
                 .01                .012                .015                  .4                   0
#fctID22-1 fctID22-2 fctId22-3 fctID22-4 fctID22-5
         3         3         0         0         0
#        Fscale_22-1         Fscale_22-2         Fscale_22-3         Fscale_22-4         Fscale_22-5
                   0                   0                   0                   0                   0
#      Eps_rate_22-1       Eps_rate_22-2       Eps_rate_22-3       Eps_rate_22-4       Eps_rate_22-5
                 .01                  .4                   0                   0                   0
#fctID33-1 fctID33-2 fctID33-3 fctID33-4 fctnID33-5
        3          3         0         0          0
#        Fscale_33-1         Fscale_33-2         Fscale_33-3         Fscale_33-4         Fscale_33-5
                   0                   0                   0                   0                   0
#      Eps_rate_33-1       Eps_rate_33-2       Eps_rate_33-3       Eps_rate_33-4       Eps_rate_33-5
                 .01                  .4                   0                   0                   0
#   Iflag2           Eps_max12           Eps_max23           Eps_max31
        -1                   0                   0                   0
#fctID12-1 fctID12-2 fctID12-3 fctID12-4 fctID12-5
         4         4         0         0         0
#        Fscale_12-1         Fscale_12-2         Fscale_12-3         Fscale_12-4         Fscale_12-5
                   0                   0                   0                   0                   0
#      Eps_rate_12-1       Eps_rate_12-2       Eps_rate_12-3       Eps_rate_12-4       Eps_rate_12-5
                 .01                  .4                   0                   0                   0
#fctID23-1 fctID23-2 fctID23-3 fctID23-4 fctID23-5
         5         5         0         0         0
#        Fscale_23-1         Fscale_23-2         Fscale_23-3         Fscale_23-4         Fscale_23-5
                   0                   0                   0                   0                   0
#      Eps_rate_23-1       Eps_rate_23-2       Eps_rate_23-3       Eps_rate_23-4       Eps_rate_23-5
                 .01                  .4                   0                   0                   0
#fctID31-1 fctID31-2 fctID31-3 fctID31-4 fctID31-5
         4         4         0         0         0
#        Fscale_31-1         Fscale_31-2         Fscale_31-3         Fscale_31-4         Fscale_31-5
                   0                   0                   0                   0                   0
#      Eps_rate_31-1       Eps_rate_31-2       Eps_rate_31-3       Eps_rate_31-4       Eps_rate_31-5
                 .01                  .4                   0                   0                   0
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/FUNCT/2
Y11_MAIN_BLOCK_STATIC
#                  X                   Y
                  -1              1.2E-6                                                           
                -.15              1.2E-6                                                           
                 -.1               .0012                                                           
                   0             3.42E-4                                                           
                  .8             3.42E-4                                                           
                 .85                7E-4                                                           
                 .86              9.3E-4                                                           
                   1              .00342                                                           
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/FUNCT/3
Y22_Y33_MAIN_BLOCK
#                  X                   Y
                  -1              4.5E-4                                                           
                -.22              4.5E-4                                                           
                -.14              2.5E-4                                                           
                -.12             6.84E-5                                                           
                   0             6.84E-5                                                           
                  .8             6.84E-5                                                           
                 .85              1.4E-4                                                           
                 .86             1.86E-4                                                           
                   1             6.84E-4                                                           
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/FUNCT/4
Y12_13_MAIN_BLOCK
#                  X                   Y
                  -1                2E-6                                                           
                -.35                2E-6                                                           
                 -.3                2E-4                                                           
                   0                2E-4                                                           
                  .3                2E-4                                                           
                 .35                2E-6                                                           
                   1                2E-6                                                           
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/FUNCT/5
Y23_MAIN_BLOCK
#                  X                   Y
                  -1                2E-4                                                           
                 -.3                2E-4                                                           
                -.25                2E-5                                                           
                   0                2E-5                                                           
                 .25                2E-5                                                           
                  .3                2E-4                                                           
                   1                2E-4                                                           
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/FUNCT/12
Y11_MAIN_BLOCK_DYNAMIC
#                  X                   Y
                  -1              1.2E-6                                                           
                -.15              1.2E-6                                                           
                 -.1               .0012                                                           
                   0             3.42E-4                                                           
                  .5             3.65E-4                                                           
                  .7              4.8E-4                                                           
                  .8                6E-4                                                           
                 .85                7E-4                                                           
                 .86              9.3E-4                                                           
                   1              .00342                                                           
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/FUNCT/13
Y11_MAIN_BLOCK_DYNAMIC-2
#                  X                   Y
                  -1              1.2E-6                                                           
                -.15              1.2E-6                                                           
                 -.1               .0012                                                           
                   0             3.42E-4                                                           
                  .5             3.65E-4                                                           
                  .7              5.8E-4                                                           
                  .8                7E-4                                                           
                 .85                8E-4                                                           
                 .86              9.3E-4                                                           
                   1              .00342                                                           
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
#ENDDATA
/END
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|

Comments

This material can be used with the following elements: hexahedral, 4 node tetra, 10 node tetra, and thick shells.
This material is based on material /MAT/LAW28 (HONEYCOMB) + strain rate dependency.
Material orthotropic coordinate system for each element (directions 1, 2, and 3) are specified in the property card /PROP/TYPE6 either through a given skew system or related to element coordinate system.

Figure 1.
All element degrees of freedom are fully uncoupled.
Elastic case example:

$σ_{11} = E_{11} ε_{11}$

$σ_{12} = G_{12} ε_{12}$

$σ_{22} = E_{22} ε_{22}$

$σ_{23} = G_{23} ε_{23}$

$σ_{33} = E_{33} ε_{33}$

$σ_{31} = G_{31} ε_{31}$

For each tension/compression and shear direction, the true stress as function of a true volumetric strain

μ

, or a true strain

ε

can be specified.

Sign conventions for strain are:

The stress values should always be positive. The following sign conventions for strain are used:

Strain Definition	Compression	Tension
Volumetric strain (`Iflag`₁ =0)	+	-
Strain (`Iflag`₁ =1)	-	+
Strain (`Iflag`₁ =-1)	+	-

For large strain formulations defined in the property using I_smstr > 1:(1)
$μ = (\frac{ρ}{ρ_{0}} - 1) = (\frac{V_{0}}{V} - 1) ε = \ln \frac{l}{l_{0}}$

For small strains defined in the property using I_smstr = 1:(2)
$μ = - (ε_{1} + ε_{2} + ε_{3}) ε_{i} = \frac{l_{i} - l_{i 0}}{l_{i 0}}$

Where, $l_{0}$ is the initial length.
When switching from a volumetric strain formulation to a strain formulation, Iflag₁ = -1 or Iflag₂ = -1 allows the same function definition to be retained.
If one of the tension strain or shear strain failures is reached, the element is deleted.